Stop mechanism for knitting machines



Feb. 14, 1939. J. WACHSMAN 2,147,275

STOP MECHANlSM FOR KNITTING MACHINES Filed March 5, 193v 2 Sheets-Sheet 1 7a rmrr/NG' Macy/NE.

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Feb. 14} 1939. J. w cgggm m 2,14 72 75 STOP MECHANlSM FOR KNITTING MACHINES Filed March 5, 1937 2 Sheets-Sheet 2 I N V EN TOR. JA (05 min/WM Patented Feb. 14, .1939

UNITED STATES PATENT OFFICE STOP MECHANISM FOR KNITTING MACHINES r 3 Claims.

The object of this invention is to provide certain improvements in electric stop mechanisms for knitting machines of the type disclosed in my Patent No. 1,775,298, September 9, 1930. One

object of the invention is to simplify the construction disclosed in said patent and reduce the number of parts to provide greater accessibility and an easier method of installation. Another object is to provide certain improvements in the circuit closers used below the electric contact ring by means of which current is conducted to the electric circuit closers used for the purpose of stopping the machine when a thread breaks or a knot occurs. Other objects 15 of the invention are to generally improve the thread tensioning means whereby to obtain a more sure and swift operation. With the foregoing and other objects in view my invention is embodied in a stop mechanism for knitting 2o machines arranged and designed as hereinafter set forth and as illustrated in the accompanying drawings in which Fig. 1 is a diagrammatic view of my improved stop mechanism for knitting machines.

25 Fig. 2 is a side view of one type of an improved circuit closer.

Fig. 3 is a sectional view on the line 3-3 of Fi 2.

Fig. 4 is an end view of the bracket shown in 30 Fig. '2.

' Fig. 5 is a modification of, the circuit closer shown in Fig. 2 with parts broken away.

Fig. 6 is a view of an improved tension mechanism which may be used with the mechanism 35 shown in Fig. 1.

Fig. 7 is a sectional view on the line 'I-| of Fig. 6.

Fig. 8 is a still further modified and improved circuit closer. 40 Fig. 9 is a sectional detail view of a part shown in Fig. 8.

Fig. 10 is a plan view of parts shown in Fig. 8. Fig. 11 is a detail sectional view of the contact ring and support shown in Fig. 1.

45 Referring first to Fig. 1 the numeral 1 denotesa central rotating shaft which supports the several parts of the stop mechanism. This shaft is attached to the central rotating shaft of a knitting machine not shown. The illustration 50 in Fig. 1 is sometimes called a knitting machine top. Its use and the manner in which it is attached to a circular knitting machine is well known in the art.

The shaft carries a series of radial arms2which 55 support the spindles for the spools 3. Above the arms 2 there'is another set of arms 4 which carry so-called end detectors 5 which may be of the type shown in my Patent No. 1,784,560, Dec. 9, 1930. Near the top there is mounted still another set of arms 6 which carry so-called knot detectors 1 which may be of the type shown in my Reissue Patent No. 19,069 Feb. 6, 1934. The end and knot detectors are per se no part of this invention.

Beneath the arms 2 the shaft carries a disk 10 II) which supports a ring I2. To the latter there are secured brackets l3 which support a contact ring 14 in the form of a rather thin conducting metal band. The brackets I 3 are insulated from the ring I2 as shown and to one of said brackets 15 is secured a rather stiff electric supply wire I 5. The arrangement is such that when the shaft I rotates with the knitting machine which also rotates the disk ID, the ring l2 stands still being prevented from rotating by the wire I5 which is fixed to a source of electric current not shown.

Underneath the disk In there is another disk I6 which is secured to the shaft l. The disk It carries brushes H3 in slidable rubbing contact with the ring M. The brushes 3 are insulated as at I!) and carry slack take up devices each of which consists of a bracket 20 having an-arm 2| which carries eyelets 22 through which the thread passes. The bracket 20 carries a wire slack take up arm in the form of a wire spring 23 with an eyelet 24. The wire springs project under the ring l4 so that when released their springy action will throw them up into contact with the ring I4 along which they wipe due to the rotation of the shaft I and thus effect electrical connection between the ring and the shaft, the latter being grounded'as will be understood.

In operation the thread passes from the spools 3 up through the end and knot detectors and down through openings 25 and 26 and the eyelet 22 and thence down to the knitting mechanism not shown. The detectors are electrically connected by wires 27 and the brackets l3 to the contact ring M in any suitable manner, not shown. If too much slack occur or should the thread break the spring 23 will close the circuit whichas is well known operates to stop the knitting machine. The brushes I 8 serve to keep the ring l4 clean for good electrical connection with the springs 23.

In my said Patent No. 1,775,298 the contact ring is supported by long inwardly extending radial arms supported from heavy upright outside posts which interfere with accessibility. The

present construction is more centralized, has fewer parts and is easy to get at for adjustments, repair andthe like.

It sometimes happens that during the operation of the machine the spring wire arms 23 are pulled down below the eyelets 22 and get tangled up with the bracket and the thread and is prevented from again assuming normal position. If the bracket 2!] supports only one wire spring the matter is not serious but where, as is often the case, the bracket supports several slack take up wires they may easily become tangled. One object of the invention is to provide a bracket which will prevent such tangling.

Referring now to Figs. 2, 3, and 4 the slack take up device consists of a bracket 38 which supports an arm 3| having its outer free end provided with a triangularly formed cam piece In this instance the bracket supports three slack take up springs 33 and the cam has three eyelets 34 to correspond. As seen in Fig. 4 if a spring 33 should be pulled too far down so as to get below the eyelets 34, the spring will slide upwards against the inclined side 35 of the cam 34 and thereby automatically free itself. The arm 3| may be provided with an additional cam piece 32 as in Fig. 5 which is adjust-ably mounted on the arm. In this case the spring eyelet 36 is arranged between the two cam pieces of the arm.

In addition to the slack take up spring wires I may use a tension device such as shown in Figs. 6 and '7. The device may be mounted upon the arms 2| or 3| or it may be used in other places where tension is desired. A tension device such as shown in which tension is applied by a spring 40 which presses two disks 4| together while the thread is passed between them is not new. However it has been found that the spring is apt to become clogged with paraffin and fuzz from the thread and then the tension will not work, particularly when applied to very fine threads. As shown in Fig. 7 the spring is protected against dirt in that it is enclosed within two telescoping tubes 42 and 43. These slide upon each other as the spring contracts or expands and at all times protects the spring against dirt. The numeral 44, denotes a lever in threaded engagement with the tension shaft 45- for adjusting the spring.

It may also happen that a slack occurs in the thread and the latter may fall down from between the disks. To prevent this there is provided a pin upon the shaft 45 with a portion 46 which extends through the disks as shown. The pin is long enough to extend through the disks while the latter move to and fro during operation. If the thread 50 should become slack, it will fall down between the disks and be caught by the pin so that it cannot fall out altogether hence when the slack is taken up the thread is in position to be caught between the disks and the tension applied. The tension device is supported by a bracket 5| which is slidably mounted upon the arm 2| or 3|.

Figs. 8-10 illustrate a modification which includes certain advantages not obtainable with the preceeding devices. In this case the bracket 52 supports an arm 53 which carries eyelets 54 of a novel form. As seen more particularly in Fig. 9 the eyelet has a nipple 55 the upper part of which forms a fine slit or fine cut 56 produced by bending the two edges of the nipple together. The forward edges of the nipple as at 51' are cut away so that the thread will slide easily into and out of the nipple. The arm 53 has an extension 58 with eyelets 59. As seen in Fig. 8 these latter are at a lower level than the eyelets 54. The arm also supports the slack take up spring wires with eyelets 6|. In Fig. 8 the thread 50 comes from the detectors, see Fig. 1, passes down through the eyelet-nipples 55, up through the spring eyelets 6 I, through the eyelets 59 and thence down to the knitting mechanism, not shown. If the thread breaks between the needles for instance and the eyelets 59, the spring eyelets will rise and pull the thread upwards into the cut or slit 56 in the nipples. The thread is thus caught and the slack is not passed on back into the stop mechanism. The end of the thread can easily be gotten hold of and the break repaired. In the case of a mere slack in the thread the same action will take place. The spring will rise and move the thread into the slit in the nipples. Then the slack portion will pass into the knitting mechanism and when the thread is again taut, the knitting mechanism will pull the thread out of the slit in the nipples because the eyelets 59 are at a lower level than the nipples and because the pull on the thread by the knitting mechanism will move the eyelets 6| down to normal operating position so that the thread is no longer caught in the slits 56 in the eyelets 55.

The devices shown in Figs. 2-10 may be used together or separately depending upon local requirements. The brackets are all adapted to be secured to the disk I 6 in Fig. 1. The number of slack take up wire springs which may be used on any one bracket depends upon the number of bobbins used. In each case of course when the threads break the wire springs rise and contact with the fixed current supply ring 14 to stop the machine.

I claim:-

1. An apparatus of the character described including a rotating centrally disposed shaft and electric stop devices, a nonrotating contact ring for supplying current to the said devices, a disk secured to the said shaft to rotate therewith, a second non-rotating ring supported on the periphery of said disk, brackets depending from said second ring for supporting the said contact ring, means for supporting the electric stop devices ln operative relation to the said contact ring and a wire secured to one of the brackets on the said second ring to prevent rotation thereof and for supplying electric current to said contact ring.

2. A circuit closing device of the character described comprising an arm including an upstanding portion at one end thereof provided with an eyelet, a slack take up circuit closing spring on said arm provided with an eyelet for taking up the slack of a traveling thread passing through both of said eyelets, said upstanding arm portion being inclined outwardly from the said arm and having an inclined cam surface for preventing the said wire spring eyelet from being accidentally caught underneath the said arm.

3. An apparatus of the character described including a centrally disposed rotating shaft, electrical stop devices, a fixed contact ring for supplying current to said devices, a second fixed ring, brackets for supporting the fixed contact ring by the second ring, a rotating disk on said shaft for supporting said second ring and means for supplying electric current to the said fixed contact ring.

JACOB WACHSMAN. 1 

